Pfizer-BioNTech and Moderna have each created an updated booster dose formula designed to protect against original strains of the virus, as well as Omicron variants that cause most new infections. The updated Pfizer-BioNTech booster for people 5 and older uses its original formula for half of the vaccine and a new Omicron-targeted formula for the other half of the vaccine. The dosage of Pfizer’s bivalent booster for people 12 and older is 30 mcg, and its dosage for children 5 to 11 years is 10 mcg. The updated Moderna booster for people 6 and older also uses its original formula for half of the vaccine and a new Omicron-targeted formula for the other half of the vaccine. The dosage of Moderna’s bivalent booster for people 12 and older is 50 mcg, and the dosage of its bivalent booster for children 6 to 11 years is 25 mcg.

Both vaccines target the Omicron BA.4 and Omicron BA.5 variants that cause most new infections. Updated boosters are expected to provide better protection against the virus and address waning vaccine effectiveness over time.

The Novavax and Johnson & Johnson boosters cannot be used as a second booster dose and are only authorized as initial booster doses in limited situations.

The recommended vaccination schedule from the Centers for Disease Control and Prevention, including dosage, is available here.